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		Creating Tuple Key Bindings
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            <h2 class="title" style="clear: both"><a id="tuplekeybindings"></a>
		Creating Tuple Key Bindings
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      <p>
    Serial bindings were used in prior examples as key bindings, and
	keys were stored as serialized objects. In this example, a tuple
	binding is used for each key since keys will be stored as tuples.
	Because keys are no longer stored as serialized objects, the
	<code class="classname">PartKey</code>, <code class="classname">SupplierKey</code> and <code class="classname">ShipmentKey</code> classes
	no longer implement the 
    <a class="ulink" href="http://download.oracle.com/javase/1.5.0/docs/api/java/io/Serializable.html" target="_top">Serializable</a>
    
	interface (this is the only change to these classes and is not
	shown below).
</p>
      <p>
    For the <code class="classname">Part</code> key, <code class="classname">Supplier</code> key, 
    and <code class="classname">Shipment</code> key, the
	<code class="classname">SampleViews</code> class was changed in this example to create a
	custom 
    <a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleBinding.html" target="_top">TupleBinding</a>
    
	instead of a 
    <a class="ulink" href="../../java/com/sleepycat/bind/serial/SerialBinding.html" target="_top">SerialBinding</a>.
	The custom tuple key binding classes are defined further below.
</p>
      <a id="tuple_sampleviews"></a>
      <pre class="programlisting"><strong class="userinput"><code>import com.sleepycat.bind.tuple.TupleBinding;
...</code></strong>
public class SampleViews
{
    ...
    public SampleViews(SampleDatabase db)
    {
        ...
        ClassCatalog catalog = db.getClassCatalog();
<strong class="userinput"><code>        EntryBinding partKeyBinding =
            new PartKeyBinding();
        EntityBinding partDataBinding =
            new PartBinding(catalog, PartData.class);
        EntryBinding supplierKeyBinding =
            new SupplierKeyBinding();
        EntityBinding supplierDataBinding =
            new SupplierBinding(catalog, SupplierData.class);
        EntryBinding shipmentKeyBinding =
            new ShipmentKeyBinding();
        EntityBinding shipmentDataBinding =
            new ShipmentBinding(catalog, ShipmentData.class);
        EntryBinding cityKeyBinding =
            TupleBinding.getPrimitiveBinding(String.class);</code></strong>
        ...
    }
} </pre>
      <p>
    For the City key, however, a custom binding class is not needed
	because the key class is a primitive Java type, 
    <a class="ulink" href="http://download.oracle.com/javase/1.5.0/docs/api/java/lang/String.html" target="_top">String</a>.
	For any primitive Java type, a tuple binding may be created using the 
	<a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleBinding.html#getPrimitiveBinding(java.lang.Class)" target="_top">TupleBinding.getPrimitiveBinding</a>
	
    static method.
</p>
      <p>
    The custom key binding classes, <code class="classname">PartKeyBinding</code>,
	<code class="classname">SupplierKeyBinding</code> and <code class="classname">ShipmentKeyBinding</code>, are
	defined by extending the 
    <a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleBinding.html" target="_top">TupleBinding</a>
    
	class. The 
    <a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleBinding.html" target="_top">TupleBinding</a>
    
	abstract class implements the 
    <a class="ulink" href="../../java/com/sleepycat/bind/EntryBinding.html" target="_top">EntryBinding</a>
    
	interface, and is used for one-to-one bindings between tuples and
	objects. Each binding class implements two methods for converting
	between tuples and objects. Tuple fields are read using the
	<a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleInput.html" target="_top">TupleInput</a>
	
	parameter and written using the 
    <a class="ulink" href="../../java/com/sleepycat/bind/tuple/TupleOutput.html" target="_top">TupleOutput</a>
    
	parameter.
</p>
      <a id="tuple_partkeybinding"></a>
      <pre class="programlisting"><strong class="userinput"><code>import com.sleepycat.bind.tuple.TupleBinding;
import com.sleepycat.bind.tuple.TupleInput;
import com.sleepycat.bind.tuple.TupleOutput;
...</code></strong>
public class SampleViews
{
...

    <strong class="userinput"><code>private static class PartKeyBinding extends TupleBinding
    {
        private PartKeyBinding()
        {
        }

        public Object entryToObject(TupleInput input)
        {
            String number = input.readString();
            return new PartKey(number);
        }

        public void objectToEntry(Object object, TupleOutput output)
        {
            PartKey key = (PartKey) object;
            output.writeString(key.getNumber());
        }
    }
    ...
    private static class SupplierKeyBinding extends TupleBinding
    {
        private SupplierKeyBinding()
        {
        }

        public Object entryToObject(TupleInput input)
        {
            String number = input.readString();
            return new SupplierKey(number);
        }

        public void objectToEntry(Object object, TupleOutput output)
        {
            SupplierKey key = (SupplierKey) object;
            output.writeString(key.getNumber());
        }
    }
    ...
    private static class ShipmentKeyBinding extends TupleBinding
    {
        private ShipmentKeyBinding()
        {
        }

        public Object entryToObject(TupleInput input)
        {
            String partNumber = input.readString();
            String supplierNumber = input.readString();
            return new ShipmentKey(partNumber, supplierNumber);
        }

        public void objectToEntry(Object object, TupleOutput output)
        {
            ShipmentKey key = (ShipmentKey) object;
            output.writeString(key.getPartNumber());
            output.writeString(key.getSupplierNumber());
        }
    }</code></strong>
    ...
} </pre>
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